PT6958_10 Datasheet, PDF (5/16 Pages) Princeton Technology Corp – LED Driver IC

PT6958
FUNCTION DESCRIPTION
COMMANDS
A command is the first byte (b0 to b7) inputted to PT6958 via the DIN Pin after STB Pin has changed from “HIGH” to
“LOW” State. If for some reason the STB Pin is set to “HIGH” while data or commands are being transmitted, the serial
communication is initialized, and the data/commands being transmitted are considered invalid.
COMMAND 1: DATA SETTING COMMANDS
The Data Setting Commands executes the Data Write or Data Read Modes for PT6958. The data Setting Command, the
bits 5 and 6 (b4, b5) are ignored, bit 7 (b6) is given the value of “1” while bit 8 (b7) is given the value of “0”. Please refer
to the diagram below.
When power is turned ON, bit 4 to bit 1 (b3 to b0) are given the value of “0”.
MSB
LSB
0 1 - - b3 b2 b1 b0
Not Relevant
Data Write & Read Mode Settings:
00: Write Data to Display Mode
10: Read Key Data
Address Increment Mode Settings (Display Mode):
0: Increment Address after Data has been Written
1: Fixed Address
Mode Settings:
0: Normal Operation Mode
1: Test Mode
PT6958 KEY MATRIX & KEY INPUT DATA STORAGE RAM
PT6958 Key Matrix consists of 6 x 4 array as shown below:
Each data entered by each key is stored as follows and read by a READ Command, starting from the last significant bit.
When the most significant bit of the data (SG6, b7) has been read, the least significant bit of the next data (SG1, b0) is
read.
K1…………………K4 K1…………………K4
SG1/KS1
SG3/KS3
SG5/KS5
SG2/KS2
SG4/KS4
SG6/KS6
Reading
Sequence
b0………………….b3 b4………………….b7
V2.3
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